For at least two hours every day, Ms Starry Lee Wai King would park herself outside a metro station as early as dawn so she could catch commuters on their way to work.

With the Legislative Council (Legco) election just four days away, it is critical for the 42-year-old chairman of the Democratic Alliance for the Betterment and Progress of Hong Kong (DAB) to reach out to as many voters as she can.

Unlike Ms Lee, who is well- known as she helms the city's largest pro-Beijing party, Mr Kenny Wong Chun Kit, 29, a first-time contender from the 19-month-old party Youngspiration, is a relative unknown. He feels the one-month campaign period does not give him enough time to reach out to the one million voters in the New Territories West constituency, where he is fighting for a seat.

Exacerbating this handicap is the small campaign budget of only HK$200,000 (S$35,000) for himself and the other candidate on his list. As a measure of the budget's size, their funding cap is around HK$3 million.

Mr Wong and his team have had to rely heavily on social media to reach out to more voters, volunteers and donors.

And social media has proven to be a powerful tool for Mr Wong, who quit his financial consultant job to enter politics last month. Once, he managed to mobilise hundreds of volunteers - via a message sent on Telegram app - to help him mail out 350,000 campaign promotion leaflets to registered voters.

Observers say there is a new wave of candidates like Mr Wong who are reshaping how campaigning is done in the Legco polls. TV advertisements, for one, have been phased out in these elections.

There is also a record high number of young candidates in the race, the first major electoral vote since students camped out on the streets of downtown Central district almost two years ago to push for greater democracy. Seventeen are aged 35 and below, compared to three in 2012.

Many of these candidates and their parties are known as "localists", a new term referring to those who want to protect Hong Kong's autonomy and its culture and identity.

A total of 213 candidates from 84 lists of candidates - and 35 political parties - are competing for 35 seats in five geographical constituencies In 2012, there were 67 lists and a total of 216 candidates.

Lists of candidates are put up by parties or individuals for each of the five constituencies. Each constituency has several seats, with, for example, Kowloon East having five and New Territories East nine.

The higher number of young candidates is an indication of how Hong Kong's political landscape has shifted since the 10-week street occupation, sounding alarm bells in the former British colony as well as the Chinese leadership in Beijing.

Analysts say the Occupy Central movement and the Mong Kok riots early this year - where protesters clashed with police - are two events that have contributed to a political awakening among the young.

Many young people are now willing to step forward to have their voices heard, said political commentator Ching Cheong.

To make up for their inexperience and limited budget, the young candidates are leveraging on social media to reach out to voters.

They produce their own promotional videos, hold live broadcasts on Facebook, with some writing their own campaign songs, and take part in election forums on Internet radio and TV shows. Another first-time candidate Nathan Law said: "It is very important to promote our campaign online because the younger generation browse the Internet for information."

The chairman of four-month-old Demosisto, who is running for a seat in Hong Kong Island, is hoping to gain the support of young voters who are known to have been inactive in past elections.

Voting is not compulsory in Hong Kong and the voting age is 18. A study by the South China Morning Post shows eligible voters aged under 35 have been the least active among voters of three different age groups (18-35; 36-60; and 61 and above) from 2008 to last year.

In the last Legco polls in 2012, only 42.3 per cent of voters aged between 18 and 20 cast their ballots, the report on Aug 25 said. This was the lowest figure in all age groups.

At 23, Mr Law is the youngest of 15 candidates fighting over six seats on Hong Kong Island, where one in three voters is aged above 60.

Mr Law knows he needs to work hard to win over the elderly voters. His party has produced several videos to explain the ideology of localism to older voters.

On his party's use of social media, he says many elderly folk own a smartphone and know how to access Facebook. But Demosisto is leaving no stones unturned.

"I would go to the wet market and Chinese restaurants to talk to them and convince them that I am their best choice," said Mr Law, who added that his party sets up daily campaign booths at high-traffic places, like the outside of metro stations.

Seeing how the younger candidates could be having an edge over him on social media, veteran politician Leung Kwok Hung, 60, also got a team to help him update his Facebook page.

"During an election campaign, it is important for voters to know how a candidate performs and we used to depend on the mainstream media. But these media outlets may not report about people like me. So I have to post more updates on Facebook," said the former construction worker from the League of Social Democrats, who is nicknamed Long Hair.

Political analysts say the power of social media is not to be underestimated, citing localist activist Edward Leung's successful online campaign for the New Territories East by-election in February.

Even though he did not clinch the seat, the high-profile activist from Hong Kong Indigenous, which was allegedly behind the Mong Kok riots, managed to win 66,500 or 15.4 per cent of the votes, defying predictions that he would fail to garner three per cent of the votes and forfeit the HK$50,000 deposit.

"During the by-election, people got to know about me via Facebook. They believe in me even though they have never met me personally. And they came out to help my campaign," Mr Leung told The Straits Times. One of six candidates barred from Sunday's polls, he runs Younginspiration's campaign.

For Ms Lee of DAB, while the power of social media is not to be underestimated, a good handshake leaves a deeper impression."It is only when you get out there to meet and greet the voters that you can see their expressions and know if they are supportive of you."